Insights

Google Lighthouse Performance

The Google Lighthouse performance score is a metric that measures the speed and performance of a website. It’s an overall score that ranges from 0 to 100 and is generated based on a number of different performance metrics, such as the time it takes for a website to load, the time it takes for a website to become interactive, the size of the resources used by the website, and other factors that impact the user experience.

A high performance score in Google Lighthouse indicates that a website is fast and responsive, which can lead to a better user experience and improved search engine rankings. On the other hand, a low performance score can indicate that a website is slow and unresponsive, and can negatively impact the user experience.

Mobile Performance
33%
Desktop Performance
66%

Core Web Vitals

Core Web Vitals are a set of specific factors that Google considers important in a webpage’s overall user experience. Core Web Vitals are made up of three specific page speed and user interaction measurements: Largest Contentful PaintFirst Input Delay, and Cumulative Layout Shift.

VitalMobileDesktopTarget
Largest Contentful Paint5.6 s2.7 s< 2.5 s
First Input Delay390 ms120 ms< 100ms
Cumulative Layout Shift0.1710.24 0.1

Tracking scripts

All the tracking scripts on the site generated ~337 KB of data

A tracking script is a code snippet designed to track the flow of visitors who visit a website. Media, advertising, and analytics organisations will provide a script to add to your website that sends data directly to their servers. This data can then be used to measure goals and conversions, analyse user behaviour, and influence advertising campaigns.

Consider how much of this data you actually need and use? How often do you review the analytics data, and does this inform genuine change? Are you actively running social media campaigns? Consider pausing or removing tracking scripts that aren’t being actively used.

googletagmanager.com 2 164 KB
script.crazyegg.com 1 3 KB
snap.licdn.com 1 5 KB
connect.facebook.net 2 138 KB
google-analytics.com 2 21 KB
analytics.google.com 1 0 B
stats.g.doubleclick.net 2 582 B
cdn.linkedin.oribi.io 1 457 B
px.ads.linkedin.com 3 3 KB
facebook.com 2 726 B
linkedin.com 1 2 KB

Opportunities

Optimise images

By optimising the following images, roughly 211 KB could be removed from the transfer size, about 9%. This would reduce the CO2 generated per page load from 0.52g grams to 0.48 grams.

Images should be optimised for the web for several reasons:

  1. Reduced file size: Optimizing images can result in a smaller file size, which can help to reduce the amount of data that needs to be downloaded. This can lead to faster page load times and improved performance.
  2. Improved user experience: Optimising images can help to improve the overall user experience, as pages with optimised images load faster and are more responsive.
  3. Lower emissions: Optimising images can help to reduce the emissions associated with data transfer, as less data needs to be transmitted over the network.
  4. Better accessibility: Optimising images can make them more accessible to users with slower connections or limited data plans.
college-street-cycleway-reopens.jpg 328 KB 14% 211 KB

Subset large font files

Fonts should be subsetted to reduce the file size, improve performance, and reduce emissions. Subsetting a font involves removing any characters that are not needed for a particular use case, resulting in a smaller file size and faster page load times. Some specific reasons why fonts should be subsetted include:

  1. Reduced file size: Subsetting a font removes any unused characters, which can result in a smaller file size. This can help to reduce the amount of data that needs to be downloaded, leading to faster page load times and lower emissions.
  2. Improved performance: Fonts that are subsetted are faster to load and render than fonts that are not subsetted. This can help to improve the overall performance of a website, leading to a better user experience.

Overall, subsetting fonts is a good practice for anyone looking to optimize the performance and reduce the emissions of a website of a website.

f0cbab32-010c-4ff1-8be8-7d74011f2548.woff2 ~32 KB ~14 KB
284e66f2-886a-4e0f-a801-ff7b25fd52af.woff2 ~31 KB ~13 KB
b8421fb4-cff3-4723-b650-b08140b93f9b.woff2 ~27 KB ~9 KB
21dccc15-7fcb-4c2b-bc15-2ce6b1d9407b.woff2 ~27 KB ~9 KB
46dd84ea-bb96-46da-973b-d7fcca46437e.woff2 ~25 KB ~8 KB

First Contentful Paint

First Contentful Paint (FCP) is a performance metric that measures the time it takes for the first piece of content to be rendered on the screen when a user navigates to a web page. This content can be any visual element on the page, such as text, images, or a background color.

FCP is important because it directly affects the perceived speed of a website, and can impact user engagement and conversion rates. A faster FCP can lead to a better user experience and improved performance.

Here are a few ways you can optimise your FCP:

  1. Optimise images: Large, unoptimised images can slow down a page’s FCP. You can optimise images by compressing them, reducing their dimensions, and choosing the right format for each image.
  2. Minimise HTTP requests: Each resource requested by a web page, such as images, scripts, and stylesheets, requires a separate HTTP request. Minimising the number of HTTP requests can help to reduce the time it takes for a page to render.
  3. Prioritize critical content: Prioritizing critical content, such as above-the-fold content, can help to ensure that users see something on the screen quickly, even if the rest of the page is still loading.
  4. Reduce server response time: A slow server response time can significantly impact FCP. Optimizing server-side code and server settings can help to reduce response times and improve FCP.
  5. Use a performance monitoring tool: There are many tools available that can help you monitor your website’s performance, including FCP. These tools can help you identify performance issues and track your progress as you implement optimizations.
MobileDesktop
Score37%94%
Timing3.4 s0.8 s

Largest Contentful Paint

MobileDesktop
Score17%42%
Timing5.6 s2.7 s

Total Blocking Time

MobileDesktop
Score12%92%
Timing1,610 ms140 ms

Cumulative Layout Shift

MobileDesktop
Score70%52%
Timing0.1710.24

Speed Index

MobileDesktop
Score40%56%
Timing6.4 s2.1 s

Time to Interactive

MobileDesktop
Score9%96%
Timing14.3 s1.9 s

Max Potential First Input Delay

MobileDesktop
Score19%92%
Timing390 ms120 ms

First Meaningful Paint

MobileDesktop
Score64%94%
Timing3.4 s0.8 s

Properly size images

MobileDesktop
Score100%93%
InsightPotential savings of 236 KiB

Reduce unused CSS

MobileDesktop
Score27%71%
InsightPotential savings of 587 KiBPotential savings of 587 KiB

Reduce unused JavaScript

MobileDesktop
Score0%60%
InsightPotential savings of 576 KiBPotential savings of 577 KiB

Efficiently encode images

MobileDesktop
Score67%93%
InsightPotential savings of 41 KiBPotential savings of 45 KiB

Serve images in next-gen formats

MobileDesktop
Score44%93%
InsightPotential savings of 154 KiBPotential savings of 211 KiB

Reduce initial server response time

MobileDesktop
GradeFailFail
InsightRoot document took 1,140 msRoot document took 1,080 ms

Remove duplicate modules in JavaScript bundles

MobileDesktop
Score88%100%
InsightPotential savings of 3 KiBPotential savings of 3 KiB

Avoid serving legacy JavaScript to modern browsers

MobileDesktop
Score88%97%
InsightPotential savings of 33 KiBPotential savings of 33 KiB

Avoids enormous network payloads

MobileDesktop
Score96%95%
InsightTotal size was 2,283 KiBTotal size was 2,341 KiB

Serve static assets with an efficient cache policy

MobileDesktop
Score28%27%
Insight13 resources found12 resources found

Avoid an excessive DOM size

MobileDesktop
Score85%86%
Insight895 elements883 elements

JavaScript execution time

MobileDesktop
Score52%97%
Timing3.3 s0.8 s

Minimizes main-thread work

MobileDesktop
Score33%96%
Timing5.0 s1.5 s